The present invention relates in general to the design and construction of a workpiece placement system for picking and placing a workpiece on a product being manufactured. More particularly, the present invention relates to a workpiece placement system having a telescopic arm with a suction force for holding the workpiece in place during the extension of the arm.
Robots, mechanical arms, automated assembly devices, and workpiece placement systems are used in production and manufacturing processes to pick and place objects. It has become increasingly desirable to utilize automated assembly techniques to perform repetitive tasks previously done by humans. Further, robots and mechanical arms can function in a manufacturing environment which is dangerous to the welfare of a human because of the presence of welding, caustic chemicals, and unguarded machining operations.
In the past, designers of robots, mechanical arms, automated assembly devices, and workpiece placement systems have generally used a combination of mechanical fingers, grippers, pneumatic cylinders, and hydraulic cylinders to pick and place a workpiece on a product being assembled. One common limitation of many of the prior systems utilized to pick and place small objects in a manufacturing process has been that the prior devices have been overly complicated, bulky, and of limited capabilities.
One prior approach to holding a small object in place during the placement stage has been to use a magnetic head. Often, the magnetic heads have proven problematic in releasing the workpiece from the assembly arm for placement on the product being manufactured. Additionally, the use of a magnetic head inherently limits the flexibility of the apparatus because workpieces that are not magnetically attractable can not be used with the device. Therefore, in todays marketplace a system having a magnetic head minimizes the flexibility of the manufacturing operation, and potentially impacts the quality of the finished goods due to the unreliability of releasing the workpiece from the device.
Another approach to retaining a workpiece on a robotic arm, or automated assembly device has been to utilize a gravitational and/or inertial force. Inherently, a system that utilizes gravity to hold the workpiece in place on a mechanical arm limits the applicability thereof. This limitation on the movement of the mechanical arm relative to the product being assembled decreases the flexibility of the device.
The two prior approaches have limitations that reduce the flexibility of the system and reduce or eliminate the cost effectiveness of there use. The inability to consistently release a magnetically attractable workpiece at a precise location, and the limitation on the movement of a mechanical arm that holds a workpiece in place through gravity greatly decreases the economic incentive to use these devices.
Even with the variety of early designs there remains a need for a workpiece placement system with a vacuum suction force for holding the workpiece in place while it is being placed on a product being manufactured. The present invention satisfies this need in a novel and unobvious way.